1. Field of the Invention
The present invention relates to an exposure apparatus for transferring a specific patter of image from a mask to a photosensitive substrate, a method of producing the exposure apparatus, and a method of producing device with the exposure apparatus, and particularly, to a technology for detecting the position of the photosensitive substrate while monitoring alignment mark on the mask and alignment mark on the photosensitive substrate.
2. Related Background Art
It is common, in an exposure apparatus applied for performing a lithography process in manufacturing semiconductor devices, liquid crystal devices, and other relevant devices, to monitor alignment marks on the mask and the photosensitive substrate with an alignment microscope viewing from above the mask for positioning the mask and photosensitive substrate (for example, a wafer or a glass coated with photosensitive material such as photoresist). Some of techniques for detecting the position of a photosensitive substrate are a TTL (through the lens) alignment method (laser step alignment or LSA) using non-exposure light and projection optics as disclosed in Japanese Patent Laid-open Publication (Sho)60-130742 (U.S. Pat. No. 4,677,301), an off-axis alignment method (field image alignment or FIA) using a wide band of non-exposure light as disclosed in Japanese Patent Laid-open Publication (Sho)62-171125, and a TTR (through the reticle) alignment method (auto step alignment or ASA) using exposure light through reticle.